The use of a 'first-wave' model to study the effect of nutrition on ovarian follicular dynamics and ovulation rate in the sheep
| Autor: | C. Viñoles, B. L. Paganoni, John Milton, Graeme Martin, Kristy Glover, Dominique Blache, Margaret Blackberry |
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| Rok vydání: | 2010 |
| Předmět: |
Blood Glucose
Ovulation Embryology medicine.medical_specialty medicine.medical_treatment media_common.quotation_subject Blood sugar Estrous Cycle Biology Models Biological Insulin-like growth factor Endocrinology Ovarian Follicle Internal medicine Follicular phase medicine Animals Insulin-Like Growth Factor I Progesterone media_common Estrous cycle Sheep Estradiol Insulin Leptin Body Weight Obstetrics and Gynecology Cell Biology Reproductive Medicine Body Constitution Animal Nutritional Physiological Phenomena Female Follicle Stimulating Hormone Algorithms Hormone |
| Zdroj: | Reproduction (Cambridge, England). 140(6) |
| ISSN: | 1741-7899 |
| Popis: | We have developed an experimental model in which groups of ewes are simultaneously experiencing the first ovarian follicular wave of their oestrous cycle. We used this ‘first-wave model’ in a 2×2 factorial experiment (ten ewes per group) to study the effect of body condition (BC) and a short-term supplement on follicular dynamics and ovulation rate. The ‘first-wave’ was established by giving ewes three injections of prostaglandin (PG), 7 days apart. The 6-day supplement (lupin grain) began 2 days after the second PG injection and continued until the third. Follicles were studied by ultrasound, and blood was sampled to measure glucose and hormones. The supplement increased (PPP=0.06). The supplement tended to increase the number of 3 mm follicles (P=0.06). Compared with low-BC ewes, high-BC ewes had more follicular waves (PPP=0.09). Leptin and insulin concentrations remained high until the end of supplementation in high-BC ewes, whereas they decreased after the third day of supplementation in low-BC ewes. In conclusion, high concentrations of metabolic hormones in fat ewes are associated with the development of more follicular waves. When a supplement is superimposed on this situation, changes in glucose and metabolic hormones allow more follicles to be selected to ovulate. |
| Databáze: | OpenAIRE |
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